From 19b678f50831189c3206a612d16bdc7e4084e013 Mon Sep 17 00:00:00 2001
From: Kadir Can Ozden <101993364+bysiber@users.noreply.github.com>
Date: Fri, 20 Feb 2026 14:28:59 +0300
Subject: [PATCH 1/3] Fix wrong parameter name in
 namedtuple_dict_structure_factory

The call to make_dict_structure_fn_from_attrs passes
_cattrs_use_detailed_validation but the function expects
_cattrs_detailed_validation. Because **kwargs catches the misnamed
parameter as an attribute override, detailed_validation is silently
ignored and always falls back to the converter default.
---
 src/cattrs/cols.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/cattrs/cols.py b/src/cattrs/cols.py
index 64e4f2c7..d1d22ee8 100644
--- a/src/cattrs/cols.py
+++ b/src/cattrs/cols.py
@@ -277,7 +277,7 @@ def namedtuple_dict_structure_factory(
             cl,
             converter,
             _cattrs_forbid_extra_keys=forbid_extra_keys,
-            _cattrs_use_detailed_validation=detailed_validation,
+            _cattrs_detailed_validation=detailed_validation,
             _cattrs_use_linecache=use_linecache,
             **kwargs,
         )

From fca1f9513a0079e36048b0c10a0439434f3551f3 Mon Sep 17 00:00:00 2001
From: Kadir Can Ozden <101993364+bysiber@users.noreply.github.com>
Date: Fri, 20 Feb 2026 16:51:44 +0300
Subject: [PATCH 2/3] Add regression test and changelog for namedtuple
 detailed_validation fix

Add a test that verifies the detailed_validation parameter passed
to namedtuple_dict_structure_factory is actually used and not
silently ignored. Also add a HISTORY.md entry for the fix.
---
 HISTORY.md           |  2 ++
 tests/test_tuples.py | 28 ++++++++++++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/HISTORY.md b/HISTORY.md
index f8f7df14..452e7b7e 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -15,6 +15,8 @@ Our backwards-compatibility policy can be found [here](https://github.com/python
 
 - Fix an `AttributeError` in `cattrs` internals that could be triggered by using the `include_subclasses` strategy in a `structure_hook_factory`
   ([#721](https://github.com/python-attrs/cattrs/issues/721), [#722](https://github.com/python-attrs/cattrs/pull/722))
+- Fix the `detailed_validation` parameter being passed under the wrong name in {func}`namedtuple_dict_structure_factory <cattrs.cols.namedtuple_dict_structure_factory>`, causing it to be silently ignored.
+  ([#723](https://github.com/python-attrs/cattrs/pull/723))
 
 ## 26.1.0 (2026-02-18)
 
diff --git a/tests/test_tuples.py b/tests/test_tuples.py
index 4fcfd85e..0877ebfa 100644
--- a/tests/test_tuples.py
+++ b/tests/test_tuples.py
@@ -141,3 +141,31 @@ class Test(NamedTuple):
 
     assert isinstance(exc, ForbiddenExtraKeysError)
     assert exc.extra_fields == {"b"}
+
+
+def test_dict_namedtuples_detailed_validation():
+    """Passing detailed_validation to namedtuple_dict_structure_factory works.
+
+    Regression test for the parameter being passed under the wrong name.
+    """
+
+    class Test(NamedTuple):
+        a: int
+
+    # Create a converter that does NOT use detailed validation by default.
+    c = Converter(detailed_validation=False)
+
+    # But explicitly enable it in the factory.
+    c.register_structure_hook_factory(
+        lambda t: t is Test,
+        lambda t, conv: namedtuple_dict_structure_factory(
+            t, conv, detailed_validation=True
+        ),
+    )
+
+    # With detailed validation, structuring errors should be wrapped
+    # in a ClassValidationError instead of being raised directly.
+    from cattrs.errors import ClassValidationError
+
+    with raises(ClassValidationError):
+        c.structure({"a": "not_an_int"}, Test)

From 5fd1c7f89f6c5f19b91cc5f2758a0fbf7740730b Mon Sep 17 00:00:00 2001
From: Tin Tvrtkovic <tinchester@gmail.com>
Date: Wed, 4 Mar 2026 00:23:52 +0100
Subject: [PATCH 3/3] Fix namedtuple validation test

---
 tests/test_tuples.py | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/tests/test_tuples.py b/tests/test_tuples.py
index 0877ebfa..c1a9562c 100644
--- a/tests/test_tuples.py
+++ b/tests/test_tuples.py
@@ -11,7 +11,7 @@
     namedtuple_dict_unstructure_factory,
 )
 from cattrs.converters import Converter
-from cattrs.errors import ForbiddenExtraKeysError
+from cattrs.errors import ClassValidationError, ForbiddenExtraKeysError
 
 
 def test_simple_hetero_tuples(genconverter: Converter):
@@ -158,14 +158,11 @@ class Test(NamedTuple):
     # But explicitly enable it in the factory.
     c.register_structure_hook_factory(
         lambda t: t is Test,
-        lambda t, conv: namedtuple_dict_structure_factory(
-            t, conv, detailed_validation=True
-        ),
+        lambda t, conv: namedtuple_dict_structure_factory(t, conv, True),
     )
 
     # With detailed validation, structuring errors should be wrapped
     # in a ClassValidationError instead of being raised directly.
-    from cattrs.errors import ClassValidationError
 
     with raises(ClassValidationError):
         c.structure({"a": "not_an_int"}, Test)